Lincoln Electric MEC 4 Mounting instructions

WELDING TORCH
MEC 4
SAFETY INSTRUCTIONS FOR USE AND MAINTENANCE
DEVICE No
W000315606 - W000315607 - W000315610 - W000315611 - W000315612
EDITION : EN Instructions for use REF: 8695 9007
REVISION : F
DATE : 06-2018 Original instructions

Thank for the trust you have expressed by purchasing this equipment, which
will give you full satisfaction if you follow its instructions for use and
maintenance.
Its design, component specifications and workmanship comply with
applicable European directives.
Please refer to the enclosed CE declaration to identify the directives
applicable to it.
The manufacturer will not be held responsible where items not recommended
by themselves are associated with this product.
For your safety,there follows a non-restrictive list of recommendations or
requirements, many of which appear in the employment code.
Finally we would ask you kindly to inform your supplier of any error which
you may find in this instruction manual.

8695 9007
MEC 4 I
CONTENTS
A - SAFETY INSTRUCTIONS............................................................................................................1
1 - AIRBORNE NOISE .............................................................................................................2
B - DESCRIPTION .............................................................................................................................3
1 - PRESENTATION ................................................................................................................3
2 - CHARACTERISTICS OF THE MEC 4 TORCH..................................................................4
3 - TORCH COOLING..............................................................................................................5
4 - TORCH BODY DESCRIPTION...........................................................................................6
5 - DELIVERY CONDITION .....................................................................................................8
6 - DIMENSIONS AND FASTENING.......................................................................................9
C - USE...............................................................................................................................................10
1 - TUNGSTEN ELECTRODE .................................................................................................10
2 - SHARPENING OF ELECTRODES.....................................................................................10
3 - SHARPENING ANGLE .......................................................................................................10
4 - ADJUSTING THE ELECTRODE IN THE MEC4 TORCH...................................................11
5 - OPTION FOR TUNGSTEN 6 - 6.4 - 7 MM .........................................................................12
6 - NOZZLES............................................................................................................................12
7 - MEC4 TRAILING SHIELD OPTION W000315603 ............................................................13
8 - MAGNETIC POLES OPTION .............................................................................................14
D - CONNECTION OF THE MEC4 TORCH ......................................................................................17
1 - CONNECTION OF MEC4 W000315606/W000315607......................................................17
2 - CONNECTION OF MEC4 W000315611/W000315612......................................................18
3 - CONNECTION OF MEC4 W000315610.............................................................................20
E - MAINTENANCE............................................................................................................................21
1 - SERVICING.........................................................................................................................21
2 - TROUBLESHOOTING........................................................................................................22
3 - SPARE PARTS...................................................................................................................23
PERSONAL NOTES ..........................................................................................................................28

8695 9007
II MEC 4
REVISIONS
REVISION D 01/15
DESIGNATION
PAGE
Complete update
REVISION E 03/15
DESIGNATION
PAGE
Update
E-25
REVISION F 06/18
DESIGNATION
PAGE
To change logos

8695 9007 / F
MEC 4 A-1
A - SAFETY INSTRUCTIONS
For general safety instructions, please refer to the specific manual supplied with the equipment.
Gas shielded electric arc welding equipment
Before starting any work on the torch, make sure that the power
source is switched off.
FREEZCOOL DISCHARGE: (pink 285 cooling liquid)
W000010167 (9.6L)
W000010168 (19.3L)
Freezcool may not be discharged in large quantities in
the natural environment. Please comply with local
discharge regulations regarding COD ().
Before any discharge, contact the water department for
the rules applicable in your region.
They will need to know:
the COD of Freezcool (741000 mg/kg)
the quantity to be discharged in kg
The water department will let you know what you must
do, particularly the following:
place
quantity
time etc.
The COD (Chemical Oxygen Demand) represents the part of the product
that demands oxygen,
e.g. oxidisable mineral salts and most organic compounds.

A - SAFETY INSTRUCTIONS 8695 9007 / F
A-2 MEC 4
1 - AIRBORNE NOISE
Adjustment parameter
Acoustic pressure
level at the nearest
working stations
Laeq.1min
Peak acoustic
pressure level at the
nearest working
stations
Lpc
Acoustic pressure
level
Lwa
Welding: TIG/Alternating/Non-
pulsed
300 A ; 50 Hz ;Nac 70%
69.2 to 73.6 dB(A)
102.6 dB(C)
90 dB(A)
Welding: TIG/Alternating/Non-
pulsed
300 A ; 80 Hz ;Nac 70%
68.6 to 75.3 dB(A)
101.8 dB(C)
97 dB(A)
Welding: TIG/Alternating/Pulsed
300 A ; 50 Hz ;Nac 70% ;pulsé 5
Hz
69.3 to 72.1 dB(A)
99.8 dB(C)
95 dB(A)
Welding: TIG/Direct/Non-pulsed
200 A
68.7 to 71.4 dB(A)
103.7 dB(C)
87 dB(A)
Welding: TIG/Direct/Pulsed
200 A
68.4 to 70.4 dB(A)
98.7 dB(C)
85 dB(A)
The use of a helmet is MANDATORY during welding.

8695 9007 / F
MEC 4 B-3
B - DESCRIPTION
1 - PRESENTATION
The MEC4 torch is specially designed for inert gas shielded automatic TIG welding
using a tungsten electrode.
It addresses all the requirements for high welding quality and productivity,
regardless of the welded metals:
Carbon or low-alloy steels
Stainless steels
Light alloys
Copper
Titanium
Zirconium, etc.
It comes in:
straight version: bundle parallel to the torch body
bent version: bundle perpendicular to the torch body
offering maximum accessibility to the assembly work to be carried out.
STRAIGHT VERSION
W000315606: Version with screw-on fittings
W000315611: Quick Connector (QC) version
W000315610: Version for manual power source
BENT VERSION
W000315607: Version with screw-on fittings
W000315612: Quick Connector (QC) version

B - DESCRIPTION 8695 9007 / F
B-4 MEC 4
Both versions offer the following possibilities:
Easy removal of the electrode holder from the top of the torch body, for more
speed and no risk of upsetting the mechanical adjustment of the torch.
Pre-adjustment (outside the torch) of the emerged length of the electrode in
relation to the end of the protective nozzle. That pre-adjustment is carried out with
an adjustable tool delivered with the torch.
The parallelepiped shape of the outer body of the torch makes it easier to take
a positioning reference.
The MEC4 torch is cooled by water circulation and can easily withstand the
most stringent welding requirements up to 500A at 100% (except version
W000315610, limited to 250A at 100%.
As an option, straight and bent MEC 4 torches may be instantly fitted with the
following additions:
Nozzle with electromagnetic circuit for welding with arc oscillation or
deviation
Large diameter (6.0, 6.4 or 7 mm) electrode holder for high-intensity AC
welding of light allows.
Trailing shield additional to the nozzle for all applications requiring a high
degree of gas shielding for the melted metal. That trailing shield option is
compatible with arc oscillation.
2 - CHARACTERISTICS OF THE MEC 4 TORCH
Version with screw-
on fittings
Quick Connector
(QC) version
Manual version
Part number
Straight
W000315606
W000315611
W000315610
Bent
W000315607
W000315612
Maximum intensity
500A / 100%
250A / 100%
Weight of torch alone, ready to weld
2.6 Kg
Bundle length
1.1 m
2 m
8 m
Cooling
Number of circuits
1 water circuit
(out and back)
1 hollow fitting
quarter turn
connector
for manual station
Min. output
2.5 l/min at 3.5 bar
Striking
Principle
Double HF emission
Annular gas
Argon
10 to 38 l/min
Argon/H2
Argon/He
Helium

8695 9007 / FB - DESCRIPTION
MEC 4 B-5
3 - TORCH COOLING
For cooling the MEC4 torch in a closed circuit, the following may be used as
cooling liquid:
Either LINCOLN ELECTRIC liquid
Or demineralised water
SPECIAL LINCOLN ELECTRIC LIQUID
NEVER ADD WATER
It is ready for use:
W000010167, 9.6 L drum
W000010168, 19.3 L drum
This product is:
Antifreeze
Anti-algae
Anti-corrosion
Non toxic
Non-inflammable
DEMINERALISED WATER
It must have:
high electrical resistivity
pH close to 7
CAUTION while using water: RISK OF FREEZING
If the ambient temperature is below +5°C (with the equipment halted), the torch
cooling system must be protected from freezing during that period.
To avoid freezing, the cooling unit should be made to run (including overnight and on
weekends), by adding an electric water warming system to the water circuit.
To that end, you can connect the cooling unit and the water warming system to a
mains electricity supply that will not be interrupted overnight or on weekends.
NEVER ADD ANTIFREEZE
The level in the cooling liquid tank must be verified at regular
intervals.

B - DESCRIPTION 8695 9007 / F
B-6 MEC 4
Liquid can be lost during operation (change of parts on the torch) or through
evaporation.
If any topping up is required, it should be done:
either only with LINCOLN ELECTRIC liquid if that is the coolant being used
or only with demineralised water if that is the coolant being used
4 - TORCH BODY DESCRIPTION
The bottom of the metal body of the torch Fis threaded and has two seals Gand
H, and receives the shield gas metal nozzle J.
That nozzle is pressed on the two seals Gand Hthanks to the nozzle nut Kfitted
on the thread of the torch body F. The cooling water circulates between the two seals
Gand Hand is in direct contact with the inner wall of the shielding nozzle.
The electrode holder is made up of a knurled fastening cap A, that rotates freely on
the body of the electrode holder B.
The electrode clamp Dis fitted inside the opposite end of the electrode holder, and
thanks to the thread, the clamp seat E.
As soon as the seat Eis tightened onto the body F, the inner taper of the clamp
seat Eapplies pressure on a split taper of the clamp D, which tightens around the
electrode Cand effectively immobilises it.
The electrode holder assembly inserted from the top into the torch body Fis held
pressed by the thrust due to the tightening of the cap A.
The HF strike circuit is provided for the main electrode and the auxiliary electrode.
A
Tightening cap
B
Electrode holder assembly
C
Electrode
D
Electrode clamp
E
Clamp seat
F
Torch body
G
H
Seals
I
Auxiliary electrode
J
Shield gas nozzle
K
Nozzle nut

8695 9007 / FB - DESCRIPTION
MEC 4 B-7

B - DESCRIPTION 8695 9007 / F
B-8 MEC 4
5 - DELIVERY CONDITION
Versions W000315606, W000315607, W000315611 and W000315612
The MEC 4 torch is supplied in operating condition along with:
5 clamps for the electrode, 1.6 - 2.4 - 3.2 - 4.0 - 4.8 mm
3 shield nozzles, diameter 11 - 13 - 18 mm
1 auxiliary strike electrode
3 NERTAL 2% lanthanated tungsten electrodes, 150 mm long,
diameter 2.4 - 3.2 - 4.0 mm
1 electrode pre-adjustment rod with 10 mm spanner.
Version W000315610
The MEC 4 torch is supplied in operating condition only with:
1 clamp for the electrode, 3.2 mm
1 shield nozzle, diameter 18 mm
1 auxiliary strike electrode
1 NERTAL 2% lanthanated tungsten electrode, 150 mm long,
diameter 3.2 mm
1 electrode pre-adjustment rod with 10 mm spanner.

8695 9007 / FB - DESCRIPTION
MEC 4 B-9
6 - DIMENSIONS AND FASTENING
STRAIGHT TORCH
BENT TORCH

8695 9007 / F
C-10 MEC 4
C - USE
1 - TUNGSTEN ELECTRODE
The MEC4 torch is supplied with NERTAL 2% lanthanated tungsten torches. The
permissible mean intensity values for each diameter are as follows, with direct polarity
direct current:
Ø 1.6: up to 150A
Ø 2.4: up to 230A
Ø 3.2: up to 320A
Ø 4.0: up to 400A
Ø 4.8: up to 450A
Optimum arc stability will be achieved with intensity close to the stated maximum.
Tungsten is very oxidisable when hot, and so the electrodes must be kept shielded
with neutral gas at all times, including during the cooling period after welding. Any blue
or black colouring shows deficient shielding after welding
2 - SHARPENING OF ELECTRODES
Electrodes are sharpened with a grinding wheel.
The operation should be done with the electrode not being held manually.
Also, make sure that particles are removed along the surface line of the sharpening
taper; that reduces tungsten wear during use.
Sharpening should also be finished with fine grain abrasive, because the
resistance of the electrode during use is improved when the surface of the emissive
part is carefully finished.
Make sure that the grinding wheel is not a multi-purpose one, which could deposit
polluting particles on the electrode.
To eliminate a deformed or polluted tip before sharpening, the electrode should not
be held in a clamp or vice, and should not be struck with a hammer.
That could lead to micro-cracks at the grain joints or simply deform the structure
and lead to cracks at high temperatures, which would shorten the life of the electrode.
To reduce the length of an electrode, a kerf should be made with the wheel.
3 - SHARPENING ANGLE
This angle is not an absolute parameter, but it characterises the electronic
emission surface at the tip. That is why, for consistent welding results, care must be
taken to reproduce the angle consistently. A 40° top angle ought to be satisfactory.
Make sure that the extreme end of the tip, which is vulnerable from the time of striking,
is removed before use (with fine grain abrasive).

8695 9007 / FC - USE
MEC 4 C-11
4 - ADJUSTING THE ELECTRODE IN THE MEC4 TORCH
The erosion of the tip of the electrode during welding is significantly determined by
the purity of its gas shield, and shielding is in principle ideal at a relatively small
distance from the orifice of the torch nozzle.
The greater the emerged length of the electrode (the arc length must be added to
that length), the greater the gas flow must be, and it can be disrupted by the flow of air
in the neighbouring area:
torch movement
movement of tooling in the vicinity
ventilation or aeration close to the welding equipment.
In practice, the tool supplied with the MEC 4 torch should be adjusted so that the
electrode emerges out of the nozzle by 2 to 3 mm.
Once the tool is adjusted, electrode replacements can be made rapidly with no
adjustment, with the certainty of finding the same position.
Proceed as follows:
immobilise the electrode adjustment tool in a vice, for example
position the electrode in the electrode holder without tightening the clamp seat
too firmly, so that the electrode can still slide
insert the electrode holder in the tool by engaging the two flats fully, then
tighten the electrode holder with the 10mm spanner. The tip of the electrode
must then stop against the adjusting screw.
The length of the electrode that emerges out of the nozzle is obtained for the first
time by successively adjusting that screw immobilised by a lock nut.
26
Electrode adjustment tool
27
Adjustment

C - USE 8695 9007 / F
C-12 MEC 4
5 - OPTION FOR TUNGSTEN 6 - 6.4 - 7 MM
Large diameter tungsten electrode holder for high-intensity AC welding of light
allows.
With this system, the tungsten cannot be adjusted outside the torch. Adjustment
and tightening is done directly in the body of the torch.
12
Clamp holder
13
Clamp, diameter 6 - 6.4 - 7
14
Electrode, diameter 6 - 6.4 - 7
6 - NOZZLES
The nozzles of the MEC 4 torch are of five types, characterised by the inner
diameter of the shielding orifice:
Ø 11 must not be used at over 150A, to allow satisfactory shielding
Ø 13 limited to 250A
Ø 18 may be used up to 500A.

8695 9007 / FC - USE
MEC 4 C-13
7 - MEC4 TRAILING SHIELD OPTION W000315603
The MEC4 trailing shield option extends gas shielding, for materials that are liable
to be oxidised or for achieving better quality with stainless steel.
Only the Ø18 nozzle allows the use of the additional trailing shield.
It is cooled by an additional water circuit, which is connected directly to the torch
interface.
48
Cooling
49
Gas

C - USE 8695 9007 / F
C-14 MEC 4
8 - MAGNETIC POLES OPTION
This is a special Ø18 nozzle with integrated magnetic poles that allows work with
arc oscillation or deviation.
TIG arc oscillation makes it possible to:
improve control over the transfer of energy to the workpiece.
move back the limit at which surface defects occur.
weld imperfectly squeezed workpieces more easily.
increase the surface of the workpiece subjected to the flow of heat from the
TIG arc.
With equal power, penetration is reduced compared to stable TIG arcs; that can be
of particular benefit when the aim is to deposit precious materials with low dilution or
when multi-pass welding is needed or even only a second pass with a very fine finish
is required on visible welds in rust-proof boilerwork.
The magnetic deviation of the TIG arc towards the front extends its impact and
helps increase the electrical power used.
That can thus allow noticeably higher execution speeds. Further, an arc
conditioned in this manner will be more stable, even when the tip of the electrode
undergoes operating wear.
MAGNETIC NOZZLE ASSEMBLY
15
Nozzle with magnetic pole
16
Magnetic circuit
17
Coil

8695 9007 / FC - USE
MEC 4 C-15
ASSEMBLY OF MAGNETIC CIRCUIT ON THE TORCH
Oscillation: The line of the poles is aligned with the line of the seam to weld.
Deviation: The line of the poles is perpendicular to the line of the seam to weld.
Arc deviation must precede welding; otherwise, reverse the direction of flow of current
in the inductor by reversing the two lugs Aand B.

C - USE 8695 9007 / F
C-16 MEC 4
The poles integrated in the nozzle receive a magnetic circuit, which in turn receives
the induction coil. This type of nozzle with poles is compatible with the optional trailing
shield system. It only allows the magnetic oscillation position.